The present invention relates to a method and apparatus for dispensing the aroma of essential oils into a very large scale space or volume without the need for water.
Essential oils are distilled or collected oils of naturally occurring substances.
Essential oils are liquids extracted from plant material by pressing, solvent extraction, or steam distillation. Generally, these have been known for many years. These organic, naturally-occurring essential oils are extracted from the seeds, bark, roots, leaves, flowers, wood, balsam, resin, and fruit of plants. The oils are then redistilled or rectified to remove any unwanted materials. Essential oils easily evaporate infusing the air without leaving an oily residue behind. Some examples are pine oil, oil of eucalytus, oil of peppermint, oil of basil, oil of orange, oil of rosemary, oil of cedarwood, and oil of spearmint. The smell of these oils can be pleasing to some people. An open container can be left standing and a faint amount of the aroma of the oils will spread. There is a difficulty in diffusing the aroma of the oils into a room to a larger degree since the boiling points of these oils is about 172.degree. C.
Essential oils are extremely complex compositions consisting of hundreds of different organic compounds and trace elements. Organic compounds for many years were thought to only be made by living organisms containing a "vital force". In 1845, the German chemist Hermann Kolbe successfully synthesized acidic acid ending this organic "vital force" theory, yet the name organic compounds is still used. The following table lists the chemical families of the organic compounds in which essential oils are found.
Basic Chemistry: In general, essential oils consist of chemical compounds that have hydrogen, carbon and oxygen as their building blocks. These can be subdivided into two groups: the hydrocarbons, which are made up almost exclusively of terpenes (monoterpenes, sesquiterpenes and diterpenes); and the oxygenated compounds, mainly esters, aldehydes, ketones, alcohols, phenols and oxides; acids, lactones, sulphur and nitrogen compounds are sometimes also present.
Aldehydes: Citral, citronellal and neural are important aldehydes found notably in lemon-scented oils such as melissa, lemongrass, lemon verbena, lemon-scented eucalyptus, citronella, etc. Aldehydes in general have a sedative effect; citral has been found to have specifically antiseptic properties. Other aldehydes include benzaldehyde, cinnamic aldehyde, cuminic aldehyde and perillaldehyde.
Phenols: These tend to have a bactericidal and strongly stimulating effect, but can be skin irritants. Common phenols include eugenol (found in clove and West Indian bay), thymol (found in thyme), carvacrol (found in oregano and savory); methyl eugenol, methyl chavicol, anethole, safrole, myristicin and apiol among others.
Terpenes: Common terpene hydrocarbons include limonene (antiviral, found in 90 per cent of citrus oils) and pinene (antiseptic, found in high proportions in pine and turpentine oils); also camphene, cadinene, caryophyllene, cedrene, dipentene, phellandrene, terpinene, sabinene, and myrcene among others. Some sesquiterpenes, such as chamazulene and farnesol (both found in chamomile oil), have been the object of great interest recently because of their outstanding antiinflammatory and bactericidal properties.
Ketones: Some of the most common toxic constituents are ketones, such as thujone found in mugwort, tansy, sage and worm-wood; and pulegone found in pennyroyal and buchu but this does not mean that all ketones are dangerous. Non-toxic ketones include jasmone found in jasmine, and fenchone in fennel oil. Generally considered to ease congestion and aid the flow of mucus, ketones are often found in plants that are used for upper respiratory complaints, such as hyssop and sage. Other ketones include camphor, carvone, methone, methyl nonyl ketone and pinocamphone.
Oxides: By far the most important oxide in cineol (or eucalyptol), which stands virtually in a class of its own. It has an expectorant effect, well known as the principal constituent of eucalyptus oil. It is also found in a wide range of other oils, especially those of a camphoraceous nature such as rosemary, bay laurel, tea tree and cajeput. Other oxides include linalol oxide found in hyssop (decumbent variety), ascaridol, bisabolol oxide and bisabolone oxide.
Esters: Probably the most widespread group found in essential oils, which includes linalyl acetate (found in bergamot, clary sage and lavender), and geranyl acetate (found in sweet marjoram). They are characteristically fungicidal and sedative, often having a fruity aroma. Other esters include bornyl acetate, eugenyl acetate and lavendulyl acetate.
Alcohols: One of the most useful groups of compounds, tending to have good antiseptic and antiviral properties with an uplifting quality; they are also generally non-toxic. Some of the most common terpene alcohols include linalol (found in rosewood, lineloe and lavender), citronellol (found in rosewood, lineloe and lavender), citronellol (found in rose, lemon, eucalyptus and geranium) and geraniol (found in palmarosa); also borneol, methol, nerol, terpineol, farnesol, vetiverol, benzyl alcohol and cedrol among others.
Essential oils contain many constituents. The predominant components are terpenes and esters, but a large number of trace elements are also present. It is these trace elements that give the real essential oil its character and enhance its ability to blend with the other oils.
An example of this is Folded Orange Peel Oil. Orange Peel Oil is a concentrated product obtained by high vacuum distillation of the winterized peel oil of fresh oranges. The folding process removes much of the terpene hydrocarbon, d-limonene, while retaining the highly aromatic components. Clarified (or folded) oils have several times the potency of the original oil while maintaining the best odor modifying properties. The Valencia orange oil, for example, contains over 200 trace elements which have a synergistic or controlling effect on the desired potency. Trace elements exist in all natural essential oils at concentrations of less than one percent. Some trace elements exist at down to a few parts per trillion, e.g. 1/5th of a teaspoon (one gram) in 200 million gallons of water. It is these trace elements that provide the delicate, extremely complex nuances that give the natural oil its unique odor neutralizing quality.
A number of apparatuses are previously known for directly diffusing essential oils into a room. These include an integrally formed shallow open-top ceramic bowl having a cylindrical shell supporting it. The shell has an open front area and an integral base. Water is placed into the bowl, oils are spread upon the water, and a "tea" candle is lit and placed in through the open front area of the shell onto the base to heat the water and oils directly using the open flame.
A water buffered smokeless essential oil dispersing system is known in U.S. Pat. No. 5,725,833 using a charcoal briquette to heat water in a vessel resting thereon with the essential oils floating on top of the water.
These known systems are suitable for personal use for dispersing essential oils in a single room of reasonable size, but are entirely unsuitable when a large scale room or a very large scale room is contemplated. In this application, "large scale" means on the order of 1,000-10,000 square feet and "very large scale" means on the order of 10,000 square feet or larger. Also these systems are close to useless in the open air since the diffusion rate is so small and slow.
Other fogging systems are known for diffusing essential oils into the air require that the oil be diluted with water either before the dispersion or at the time of the dispersion. Such systems range from drum top foggers to massive size systems which are difficult to control and maintain. Many are expensive to build and to operate. All of these systems are subject to the problem that water is involved and must be supplied either a priori or simultaneously. Some difficulties are encountered with "rainout" and moisture condensation in the space where the dispersion is taking place. Such operations are almost impossible in winter.